Originally in the Constitution, the federal government did not have the power to create an income tax. Revenue depended largely on tariffs and excise taxes. During the Progressive Era (which you can thank for things like the weekend and the direct election of US Senators), an income tax was seen as a way to tax the rich and fund the government while decreasing inequality. They're rolling in their graves over the way it's implemented: The wealthier pay a lower effective tax on average than the middle class. Removing the de minimus exception created an even more regressive tax, as now regular consumers are paying the same in taxes as people ordering luxury goods. The point of the 16th Amendment was to remove the dependence on tariffs and arbitrary levys as a way of raising money for the federal government. Now, we're seeing the triple whammy of a regressive income tax, a regressive FICA tax (caps out at 175k ish), and regressive tariffs. The squeeze of the lower and middle class is now on. The income tax must be changed to be more progressive, and the Constitution amended to require it. Otherwise the middle will continue to be squeezed and the rich get even richer, which was never the intent of the 16th Amendment.